Calibrate Pressure Switch?

[Mr V]

If you have an on board compressor you really don't want the compressor to shut off at a higher pressure, in fact you will be better off selecting a switch that turns the compressor on and off at lower pressures, assuming you have selected the proper stored volume.

Take a look at the compressor's specs and you'll see that the higher the pressure it is working against the lower the CFM output.

Some examples

80psi .45cfm
90psi .43cfm
100psi .39cfm
110psi .36cfm
120psi .34cfm

Note those numbers are based on a supply voltage of 13.8 v something that a FRC robot does not have the luxury of, and with a working voltage in the 11-12v range I would expect a steeper drop off of performance.

Personally if I were to select a switch I'd choose one that turns on at ~80 psi and off by ~100 psi to minimize the refill time, the heat build up and general stress on the compressor. If you've sized your storage system properly there should never be a case where the stored pressure drops below 60 psi with a 80/100 switch.

Now if you have an off board compressor there could be an advantage to selecting a switch that shuts off at 120psi but that would be minimal compared to the commonly used 115psi switch.

Either way a switch that has its calibration screw fixed in one way or another by the mfg should not be adjusted, doing so would be considered tampering with or modifying a pneumatic component and make it illegal.